Sewing machines



June 5, 1962 I A. w. L cKwOoD SEWING MACHINES Filed Nov. 12. 1959 Jaye/afar flrf/ZW Wallaby/L alvkad .10 j W? if! .1

United States Patent 0.

3,037,472 SEWING MACHINES Arthur William Lockwood, London, England, assignor to Trubeuised Company (Registered Trust), Vaduz, Liechtenstein Filed Nov. 12, 1959, Ser. No. 852,365 Claims. (Cl. 112206) This invention relates to sewing machines and provides new or improved means for holding fabrics to be sewn and feeding them along a predetermined path past the machine needle, so as to produce a line of stitching of predetermined form.

In accordance with the invention apparatus for producing a line of stitching of predetermined form comprises a sewing machine, a work holder provided with means for securing thereto the fabrics to be stitched, means restraining the work holder against turning movement while permitting bodily movement of the work holder in any direction in its own plane, a guide rail on the work holder extending parallel to the required line of stitching, and means on the sewing machine for engaging the guide rail to locate it and effect progressive feeding movement thereof.

One form of apparatus in accordance with the invention is described below with reference to the acomipanying drawing, in which FIGURE 1 represents a perspective view of the work holder and guiding means (with a workpiece in position) and of associated parts of the sewing machine; and

FIGURE 2 is a front view of part of the same assembly.

The particular apparatus illustrated and described below is designed for making in the band of a one-piece shirt or like collar two spaced rows of stitching, parallel to one another and to the intended curved foldline of the collar, thus providing between the collar plies a pocket for the reception of a strip of flexible sheet material serving to determine the foldline, as described in the provisional specification of our copending patent application No. 34,014 of 19-57. It will be obvious, however, that the apparatus, or appropriately modified for-ms thereof, is capable of use for many other purposes.

The sewing machine of the apparatus illustrated is a twin needle, walking foot sewing machine of generally known construction but incorporating modifications (further described below) to the walking foot and to the clamping member which serves to hold the fabric being sewn during the periods when the walking foot is being moved forwardly to engage the fabric at a fresh position.

The work holding device comprises a metal base plate 1 which rests freely on the bed 2 of the sewing machine and has a straight upwardly projecting rail 3 formed along one of its rearwardly extending edges. This rail 3 is en gaged by two or more of a plurality of grooved guide rollers 4, each supported on a stub axle projecting horizontally from a bar 5 which extends rearwardly over the machine bed. The bar 5 is carried on a pair of parallel arms 6 which are slotted to receive the ends of a shaft 9, rotatably supported in a bracket fast to the bed 2 Pinions 8 fast on the shaft 9 engage racks 7 formed on or secured to the arms 6, so that the bar 5 is free to move parallel to itself, but is prevented from moving otherwise. Such lateral movement of the bar, combined with longitudinal sliding movement of the rail 3 relative to the guide rollers 4 on the bar, allows the base plate 1 to be, moved bodily in a horizontal plane to any position on the bed 2 (within the limits of movement imposed by the dimensions of the parts) but prevents any turning movement of the base plate.

The collar 11 to be sewn is laid on the upper surface of the base plate in a position accurately determined by stops 12, 13 provided on the base plate and arranged to engage the two points and the centre of the back edge of the collar top. The stops are constituted by plates having edges shaped to fit against the edges of the collar and are replaceably and adjustably secured on the base plate to allow the apparatus to be used in the manufacture of collars of different shapes and sizes. Spring clips 14, 15 mounted on the stop plates serve to clamp the collar against the base plate.

When the collar has been so positioned and secured, a cover plate 16, hinged to the base plate along the edge nearest to the rail 3, is turned down to engage over the part of the collar lying on the base plate. The free edge of the cover plate and the edge of the base plate 1 furthest from the rail 3 are curved in correspondence with the foldline of the collar, and the stops are so positioned that only the cape portion of the collar is enclosed between the base and cover plates, while the collar band (in which the stitches are to be made) projects beyond them.

Along its free edge (i.e. parallel with the required line of stitching) the cover plate 16 carries an upstanding guide rail 17, whose upper surface is notched or serrated. A block 18, supported on an arm projecting laterally from the walking foot 19 of the sewing machine, is adapted to engage the rail 17, the underside of the block being serrated to ensure operative engagement with the rail. The clamping member, which in a conventional walking foot machine is mounted on the lower end of vertically reciprocating rod 20 so as to make direct engagement with the fabric being sewn, is omitted from the machine illustrated and rod 20 carries a laterally projecting arm 21, also adapted to engage rail 17.

In operation, the clamping arm 21 is held down to secure the whole of the work holding means against movement during the period that the walking foot is raised clear of rail 17, moved forwardly, and lowered to bring block 18 into engagement with rail 17. The clamping member is then raised, and while the walking foot moves rearwardly and the needles 22 are operated to form the stitches, the interengagement of the teeth of block 18 and rail 17 ensures that the work holding means move with the walking foot. The part of the collar in which the stitches are formed is not at any period in the stitching cycle clamped against the bed 1 (the member 23 carried by the walking foot serving only to resist the upward drag produced by the withdrawal of the needles) but the immediately adjacent part of the collar is held firmly clamped between the base plate 1 and the cover plate 16 (whose undersurface is faced with plastic sponge or like m-taerial) owing to the pressure applied to guide rail 17 by block 18 on the walking foot.

It will be appreciated that the operation of the sewing machine causes the work holder to be moved progressively over the bed of the machine valong a path determined by the shape and position of the guide rail 17 on the work holder. Since the collar is accurately located in the work holder relative to this guide rail, the stitching 24 is effected along lines occupying an accurately predetermined position relative to the outline of the collar.

I claim:

1. Apparatus for producing a line of stitching of predetermined form comprising a sewing machine of the kind having a needle carried in a walking foot, a work holder provided with means for securing thereto the fabrics to be stitched, means restraining the work holder against turning movement while permitting bodily movement of the work holder in any direction in its own plane, a guide rail on the work holder extending parallel to the required line of stitching, and means mounted on said walking foot for engaging the guide rail to locate it and effect progressive feeding movement thereof.

2. Apparatus in accordance with claim 1 in which the guide rail and the operating means on the walking foot are formed with interengaging serrations.

3. Apparatus in accordance with claim 1 in which the work holding means comprise a base plate provided with means for accurately locating on its surface an article to be stitched and a cover plate hingedly connected to the base plate and adapted to overlie the article, the cover plate carrying the said guide rail, and being pressed towards the base plate to grip the article by the engagement with the rail of the feed member on the sewing machine.

4. Apparatus in accordance with claim 1 in which the Work holder carries a straight rail which extends in the general direction of the required line of stitching and is engaged by two or more guide rollers spaced longitudinally of the rail and carried on a member which is movcably secured to a stationary part of the sewing machine by means permitting said member to move only parallel to itself.

5. Apparatus in accordance with claim 4 in which the member carrying the guide rollers is carried on a pair of parallel arms having rack teeth which mesh with pinions fast on a common shaft rotatably supported in a stationary part.

References Cited in the file of this patent UNITED STATES PATENTS 1,092,038 Gerber Mar. 31, 1914 1,238,197 Rontke Aug. 28, 1917 1,403,094 Murchison Jan. 10, 1922 1,637,373 Fisher Aug. 2, 1927 2,142,487 De Boer Jan. 3, 1939 FOREIGN PATENTS 653,177 Great Britain May 9, 1951 521,518 Italy Mar. 29, 1955 

